Clean house and other ways to freak out the children!

The piano tuner came to work on the piano today, so I sent the kids to grandma's so they wouldn't try to "help" him. I stayed home and worked on cleaning up a bit of the house...I believe the kids may freak out that their toys are in their rooms and the house looks like maybe a few grown-ups live here too. I better not take too much time writing. I just have a little time sans kids, but I'll try to update you on their reaction to the house.  Shock or just a challenge to get it back to how they left it?